The present invention relates to military training equipment, and more particularly, to an improved system and method for processing signals from laser detectors worn by soldiers and carried by vehicles in simulated in war games.
For many years the U.S. Army has trained soldiers with a multiple integrated laser engagement system (MILES). One aspect of MILES involves a small arms laser transmitter (SAT) being affixed to the stock of a small arms weapon such as an M16A1 rifle or a machine gun. Each soldier is fitted with detectors on his or her helmet and on a body harness adapted to detect a infrared laser xe2x80x9cbulletxe2x80x9d hit. The soldier pulls the trigger of his or her weapon to fire a blank or blanks to simulate the firing of an actual round or multiple rounds. An audio sensor or a photo-optic detector detects the firing of the blank round(s) and simultaneously energizes a laser diode in the SAT which emits an infrared laser beam toward the target which is in the conventional sights of the weapon. Vehicles such as the HUM-VEE and tanks are also fitted with laser detectors for detecting infrared laser xe2x80x9cartillery shellxe2x80x9d hits. Soldiers and vehicles carry player units and control systems which include a microprocessor based control circuit for processing the signals from the detectors to determine if there has been a hit, the type of weapon registering the hit, and the identity of the shooter. After performing casualty assessment, the control circuit provides status information to the player, indicating on a display whether the player has been xe2x80x9ckilledxe2x80x9d, xe2x80x9cinjuredxe2x80x9d or xe2x80x9cdamagedxe2x80x9d. This in turn will tell the player his or her status in the combat training exercise. The exercise events and casualties are recorded, replayed and analyzed in detail during xe2x80x9cafter action reviewsxe2x80x9d (AARs).
In order to accurately assess the performance of soldiers during MILES-based combat training exercises it is essential that the laser detectors on the soldiers and vehicles accurately detect laser hits. Normally these detectors are equipped with a transparent window or lens that receives the infrared laser beam emitted by SAT-equipped rifle or a laser scanner transmitter on a tank gun. The infrared radiation passes through this optical element and impinges upon an infrared detector. If the window or lens is contaminated, e.g. with dirt, dust, mud or other debris, a laser hit may not be detected. A serious problem in MILES-based training exercises occurs because soldiers on occasion have been known to intentionally spread dirt, dust, mud, snow, shoe polish, or other contaminants on the window or lens of the detectors the player is wearing, or on the detectors mounted on his or her vehicle. These contaminants substantially limit or block the transmission of laser signals through the window or lens. This greatly reduces the likelihood, and in some cases completely eliminates the possibility, that they will be xe2x80x9ckilledxe2x80x9d thereby keeping them in the war game, and inaccurately reflecting their combat performance. Such incidences greatly impede the commander""s ability to accurately assess during an AAR the skill of the individual participants and the tactics employed. Accordingly there is an acute need to prevent unintentional and intentional fouling of these optical detectors. Any improvement in this regard must be designed to bar soldiers from overcoming the same.
Accordingly, it is the primary object of the present invention to provide an improved channel for processing signals from an optical detector used in simulated combat exercises.
Another object of the present invention is to provide a method of preventing soldiers from cheating during MILES-based training exercises and similar laser combat training exercises by deliberately contaminating the window, lens or cover of a soldier worn, or vehicle borne, laser optical detector.
In accordance with the present invention, an optical system for detecting contamination includes a detector mounted in a housing for detecting incident optical radiation having a predetermined wavelength and for generating signals representative thereof An optical element is mounted to the housing for allowing optical radiation received from an exterior side of the optical element to pass through the optical element and impinge upon the detector. A source or a plurality of sources of illumination may be mounted inside the housing for selectively illuminating the optical element from an interior side thereof with optical radiation having the same predetermined wavelength. A test circuit is connected to the detector for determining the presence of a predetermined amount of a contaminant on an exterior surface of the optical element based on the signals generated by the detector when the optical element is illuminated by radiation from the source of illumination.
The present invention also provides a method of preventing cheating in a simulated combat exercise. The method involves the first step of equipping a plurality of players with laser detectors for detecting simulated kills or injuries from SAT-equipped small arms weapons. The next step of the method involves electronically determining the presence of a contaminant on an exterior surface of an optical element positioned in front of a laser detector. The final step of the method involves providing an indication to a player if the contaminant is detected.